This study aims to examine the effect of flame retardants (FRs) on the mechanical and thermomechanical properties ofepoxy composites reinforced with basalt fibers. To effectively modify fire behavior, it is usually necessary to introduce significant amounts of FRs, which raises many concerns due to the potential deterioration of other functional properties, includingmechanical performance. In this work, 30 wt.% halogen-free FRs, including a two-component FR (ammonium polyphosphatewith pentaerythritol) and melamine cyanurate, were introduced into the polymer matrix. The unmodified and intumescentFR-modified epoxy resin composites reinforced with basalt fibers were subjected to static flexural test and thermomechanicalproperties assessment. The research results were correlated with the analysis of changes in the chemical composition assessedusing Fourier transform infrared spectroscopy. As a result, the saturation of the reinforcing fabrics by the modified epoxyresin was limited, which caused a different failure mechanism under static bending and impact test conditions. Both FR systems reduced the flammability of the modified epoxy laminates along with also acceptable deterioration of the mechanicalproperties. The most beneficial effects considering the combination of all the analyzed features were noted for thetwo-component FR system containing ammonium polyphosphate and pentaerythritol.